The present invention relates generally to a ventilator system and, in particular, to a ventilator system which incorporates a control valve in the ventilator circuit.
Ventilator systems are widely utilized in hospitals in order to assist patients with respiratory problems in breathing. Typically, a ventilator system includes a ventilator unit which provides a supply of air containing a predetermined percentage of oxygen. The ventilator unit is provided with a heater and a humidifier for heating the air to a predetermined temperature having a desired amount of humidity. The ventilator system further includes a ventilator conduit circuit which comprises a plurality of flexible conduits utilized to supply the heated, humidified air to the patient. The air can be introduced into the patient's lungs by means of an endotracheal tube, for example.
The ventilator unit is typically provided with a plurality of controls for regulating the inspiration and expiration of the patient. In some instances, the ventilator system is operated in a mode wherein at least a portion of the ventilator circuit is maintained at a predetermined positive pressure with respect to atmospheric pressure. This particular mode is typically referred to as a positive end expiratory pressure (PEEP) mode.
Generally, the ventilator unit is set to heat the air to a temperature above a patient's body temperature such that, after the air has passed through the ventilator circuit and is ready to enter the patient, the air will have cooled to a temperature approximately equal to the patient's body temperature. This cooling of the air throughout the ventilator circuit causes condensation within the associated conduits and thus results in water collecting in the ventilator circuit. As a result of this condensation, it is necessary for hospital personnel to periodically inspect the ventilator circuit for water accumulation and, if necessary, drain the water from the ventilator circuit.
When it is desired to drain the accumulated water from a ventilator circuit, an attendant typically disconnects the outlet of the ventilator circuit from the patient's endotracheal tube. However, when the ventilator unit is operated in certain modes such as the above described PEEP mode, the pressurized air in the ventilator circuit causes the accumulated water to spray from the outlet of the ventilator circuit over the patient and/or attendant. While the spraying of the water can be prevented by turning down the PEEP control valve on the ventilator unit, this is often impractical due to the location of the ventilator unit relative to the patient and attendant.